Street traffic signal



March 26, 1935.

c. ADLER, JR 1,995,816 STREET TRAFFIC SIGNAL Filed'Nov. 19, 1934 3Sheets-Sheet 1 March 26, 1935.

C. ADLER, JR

STREET TRAFFIC SIGNAL 3 Sheets-Sheet? Filed Nov. 19, 1934 grvuc/wbo'r//farleaz//czle/xfrg 5% W, (in? SUM/May Match 26, 1935.

C. ADLER, JR

STREET TRAFFIC S IGNAL 5 Sheets-Sheei 3 Filed Nov. 19, 1934 Patented,Mar. 26, 1935 UNITED STATES PATENT OFFICE STREET mo srGmn. V 4 CharlesAdler, In, Baltimore, Md.

Application November 19, 1934, Serial No. 753,773

3Cla'ims.

' The present invention relates to signals, and is useful in connectionwith all types of-signal systems. Primarily, however, it is adapted forpedestrian and vehicular trafllc signal systems.

The first aim of the invention is to increase or enhance the safetyfactor. Thus the present signal (1) gives an accentuated or imperativedirective eifect, and (2) particularly accommodates itself to the needsof persons who are color blind, near-sighted and to those who, accordingtotraillc authorities, do not show a normal alertness A further objectof the invention is to provide a signal which will. be economical inthatit is possible to dispense with lamps of high wattage now employed,and to use in place of them, lamps of relatively low wattage, e. g., 15to 25 watts. The saving obtained by municipalities as a result of. theinstallation of the present signal has been very substantial.

Briefly stated, the invention includes a reflector, an illuminatingapparatus such as an electric lamp, and a cover glass or lensconstituting the signal area. This latter member is constructed so thatit will cooperate with the lamp and the reflector, permitting (1) theuse of a low wattage lamp, (2) produclngan illuminated signal areavisible at a considerable distance from the signal, and (3) producing-anilluminated signal area, a portion of which is sharply illuminated whenthe signal is viewed from a relatively short distance and at an angle. 1That is, the signal area is illuminated and visible to pedestrians andvehicular traiiic moving in the lane toward the signal, and whenpedestrians or vehicular trailic are in close proximity to the signal,and for example, must look up to observe it as at the intersection, orad- Jacent thereto, a signal is sharply Presented. This is particularlyimportant in connection with ayli ht i Referring to the drawings:

Figure 1 is a top elevation indicating diagrammatically and relativelythe action ofthe signal.

Figure. 2 is a side elevation illustrating diagrammatically andrelatively the action of the 18m Figure 3 is a rear elevation of thelens or cover glass. 1

Figure 4 is a section on the line 4-40! Figure 3.

Figure 5 is a top view in section showing in detail the operation of thesignal when one form of cover glass is used.

Figure 6 is a top view in section showing in detall the operation of thesignal, when another form oi cover glass is used.

Figures 7 and 8 are detailed views or the cover contrary a lamp'of 15watts is highly eflicient glass or lens, Figure 7 being partly brokenaway in elevation, and Figure 8 being partly broken away'in section. v

Figure 9 is a front elevation of the complete signal, showing thehousing and signal areas, and- 5 Figure 10 is a detached view of anotherform of cover glass or lens included in the present in vention.

Referring to the he signal is particularly useful for controllingvehicularand pedestrian traflic. It is incorporated, for example, in theusual signal housing shown in Figure 9 embodying a green or Goindication G, a yellow or "Caution" indication Y, and a red or "Stopindication R. In some installations the yellow or caution is eliminated.1

Such signals are placed in the center of the intersection as shown inFigure 1, or at the corners of the intersection, as well understood.

Drivers of vehicles passing down the lane are able to observe and bedirected by the signal (1) at a distance, i. 'e., at a pointapproximated by the position of the vehicle V in Figure 1, and (2) at apoint at or adjacent the intersection, substantially as indicated bytheposition of the vehicles V in Figure 1. Where a pedestrian or vehicleis at the position V moving toward the signal, means are provided toclearly indicate the direction of tramc at the intersection. When thedriver reaches the position V and must, as is usually the case, look upat the signal, or view it at an angle or from an offset position, e. g.,one side or the other, likewise positive means are provided forbrilliantly and sharply illuminating a predetermined portion of thesignal area. a

In addition to accomplishing these various functions, which I find areessential to safe and satisfactory traihc direction, the presentinvention is operative at a much greater economy than signals now inuse. Present day signals employ a dilfusing lens with a highwattagelamp, for example, a lillv ratt lamp. The present invention does notrequire high wattage lamps, but on the and lamps up to 25 watts may beused. The signal has been installed in various communities and inseveral States, and has effected a considerable saving as well as provenits enhanced value as a direction means. 50

Referring to Figures 5 and 6, the signal shown in Figure 9 willhave oneor more signal elements indicated as a whole at 10-. These signalelements comprise a reflector or mirror 11, preferably of theparabolictype; lighting apparatus,

corrugated area at C 'D'.

such as an electric lamp 12 of customary design or a lamp of thecharacter shown and described in my United States Patent No. 1,869,725;and a cover glass or lens 13 illustrated in detail in Figures 3 and 4.The cover glass or lens is preferably concavo-convex as shown in Figure4 and is provided with a plurality of flutes or corrugations 14 on theconcave or interior side. The elongated filaments 15 of the lamp of myaforesaid patent will preferably be arranged so that they extend inparallel relation to the flutes or corrugations since they are offsetrelative to the focal point. This is not necessary in the case of asingle filament lamp as the filament will usually be disposed at thefocal point as shown in Figures 5 and 6.

In addition to the fluted area 14, the lens is provided, preferably onthe concave side, with a band or area 16 composed 01 a multiplicity ofprisms, as shown in Figures 3 and 4. This p'rismatic area or band in thecase of the red or ,Stop cover glass 13, extends at substantially rightangles to the flutes or corrugations, that is the band 16 intersects thecorrugations, as shown in Figures 3 and 4, to give a barrier eflfect, aswill be understood upon reference to Figures 3 and 9, where the bandextends across the diameter otthe lens and divides the same into upperand lower fluted areas. This prismatic band 16 in the case of the greenor Go cover glass is disposed parallel to thecorrugations 14, as shownin Figure 6, and imparts the impression of a clear lane, as will beappreciated upon reference to Figure 9 (G). In the case of the yellow orCaution signal, the prismatic band 16 is disposed diagonally, as shownin Figure 9, and dependent upon the positionof the signal with relationto the highway, the direction of the diagonal may be changed as shown inFigure 10.

Reierring to Figure 1, the flutes or corrugations 14 retract the lightprimarily in a horizontalplane, as indicated at A-B, and give abrilliant illumination which may be easily viewed at a considerabledistance from the signal, for example, at the point V. The flutes orcorrugations do not direct or refract any substantial portion of thelight downwardly. However, the prismatic area retracts the light in alldirections and in cooperation with the reflector and lamp, the prismaticband when viewed, for example, at a point V, below the s'ignal'and/ orat one side or the other thereof, will be sharply illuminated. In thismanner, and by means of a low wattage lamp, the signal is brilliantlygiven at a distance, and

when viewed in close proximity, as just stated,

not only is the indication brilliant, but the bands 16 are accentuatedin appearance and imperative in directive effect.

The relative horizontal spread of light pro duced by the prismatic bandis indicated by the line A'B' in Figure 1, and is not visible at sogreat a distance as the light refracted by the corrugated area. That is,the prismatic beam is short but intense, and the spread, as will beobserved, is much greater than that refracted by the corrugated area andis in all directions.

The relative spread of light in a vertical plane is illustrated inFigure 2, that of the prismatic area being indicated at CD, and that ofthe It will be observed that the downward spread, which is all that needbe considered because of the presence of the usual deflecting hood 18associated with each signal member 10, is greater to a very considerableextent in the case of the prismatic area over the fluted area. This isimportant because it assures that the prismatic area 16 will be at alltimes intensely illuminated and when viewed from the position V, thisportion of the signal area sharply stands out to give the indication.

As stated, each color lens GY--R is concaveconvex and constructed withvertical flutes on the concave side only. These flutes reflect theparallel beams of light produced by the lamp fllament and reflected bythe parabolic mirror and deflect the beam horizontally only, e. g., atan angle of about 15 on either side (see the line A-B) The fluted area0! the lens therefore serves only to slightly fan out the beam in ahorizontal plane and substantially none of thelight is deflected eitherup or down. That is, the light -is all directed parallel to the trafficlane and band 16, as shown in Figures 1, 3, 4, 5, 7, 8 and 9,

is horizontal, i. e., diametrical' and bisects the cover glass intoupper and lower fluted or corrugated areas. This produces a very wide'horizontal and vertical beam spread, so that when trafllc is stoppedbythe red indication and the vehicles pull up side by side and formseveral trafllc lines (see Figures 1 and 2) the vehicles in all of theselines will be within range at the beam spread. That is, the vehicles inall of the several lines, by reason of the spread in all directions ofthe light refracted by the prismatic area, will be within the range ofthe beam refracted by the prismatic area, whether the vision be indirect line with the signal, or oflset, i. e., at one side or the other.

The prismatic band 16 in the green lens is vertical and diametrical, asshown in Figures 2, 6 and 9, and parallel with the corrugations. Ittherefore does not produce as. great a horizontal beam spread as doesthe horizontally disposed red band, but does produce greater downward orvertical spread. Whenthe green indication is displayed, vehicles aremoving in lanes closer to the road center, past and below the level ofthe signal lamp, and the vertical prismatic band produces a beam whichencompasses the driver's vision until he has passed the signal.

In connection with the yellow or amber illumination Y, it is standardpractice to display this indication only to the lanes in which trafllcis moving and not to traflic that has been stopped by the red, 1. e., itis displayed only when or after the green is about to be extinguished.Thus the yellow or amber is displayed Just prior to the completetransfer of right of way indication to the intersecting highway, and itspurpose is to stop vehicles that have not already passed the entrance tothe intersection.

The prismatic band 16 of the Caution lens Y is disposed diametricallyand diagonally, as shown in Figures 2 and 9, and in detail in Figure 10.In the position shown in Figures 6 and 9, the beams are deflecteddownward and to the right of the signal and so as to be visible todrivers of vehicles about to pass into the intersection or about to makea right turn into the cross highway and away irom the signal. When thesignal is ward the signal in a lane located over the center of theintersection, the diagonal band in the Caution or amber lens Y shouldslant downward at an incline of about 45 from left to right, as inFigure 9. If the signal is located on the far side of the intersection,the same result is obtained by molding the band with a downward slant ofabout 45 from right to left, as shown in Figure 10. In this manner thebeam will be visible both to tramc proceeding down the center of thelane or which is drawn off to one side for the purpose of making a turninto the cross highway.

As pointed out, the prismatic band produces a wide beam for a relativelyshort distance. The remaining lens area, however, is made up of thevertical flutes and these, in combination with a parabolic reflector ormirror, project a narrower beam of great intensity in a horizontal planewhich is visible for great distances, notwithstanding that a low wattagelight source or electric lamp is employed.

As heretofore stated, I am. able to use lamps of from 15 to 25 watts andproduce-a very efllcient signal indication, at the same time obtaining avery decided economy in operation costs.

The use of the prismatic bands in combination with the fluted areas, andwith the prismatic bands in different positions for each color, as shownin Figures 2 and 9, enables the indications to be readily observed bymany color blind motorists and pedestrians as well as near-sightedpersons who traverse the intersection. Moreover, theprismatic bandsstand out in a manner to attract and awaken the senses, so that apedestrian or driver who is not on the alert will be safeguarded by theadditional attraction of the prismatic bands arranged in their severaldifferent positions. In other words, the signal aspect is much moredistinctive to everyone than the present or customary signal areas nowinuse. The hands, when viewed from a distance, appear darker than thefluted areas but on the other hand when the signal is viewed from anangle or at close range, the prismatic band appears definitely brighterand stands out sharply.

It will be observed that I have provided a signal comprising areflector, an illuminating apparatus, and a cover glass or lens whereina beam of considerable length displaying brilliantly the entire signalarea is given to trafllc moving toto which the signal is presented. Thisbeam covers substantially the entire width of the lane. Also, I haveprovided a signal wherein the signal area viewed at close range istranslated into a brilliant indication appearing as a sharply definedcontrasting area accentuating the signal and imperative in its effect.This eflect is produced by the relatively short and intense beam ofgreater spread in all directions, formed by the prismatic area, whichextends horizontally, vertically, or diagonally, as the case may be. Itis to be borne in mind that these results are now being satisfactorilyobtained by means of a low wattage lamp.

Various modifications of the invention may be resorted to, all of whichare regarded as comprehended within the appended claims.

I claim:--.

1. A signal unit for street trafllc control comprising a casing havingan opening, a lens or cover glass over said opening, and an electriclamp of appreciably low wattage in comparison with the high wattagestandard of approximately sixty watts customarily used in such units,for illuminating the lens or cover glass, said lens or cover glasshaving an area thereof capable, in combination with said low wattagelamp, of refracting a relatively narrow beam of light in a horizontalplane, and another area capable, in

combination with said low wattage lamp, of refracting an appreciablywider beam of light in a horizontal and downward direction.

2. A signal unit ,for street trafllc control comprising a casing havingan opening, a lens or cover glass over said opening, said lens or coverglass having a band, including a plurality of prisms, extending acrossthe cover glass and parallel flutes on one side of said band, and anelectric lamp of appreciably low wattage in comparison with the highwattage standard of approximately sixty watts customarily used in suchunits, said lamp disposed in said casing for 11 luminating the lens orcover glass, said lens or cover glass capable, in combination with saidlow wattage lamp, or retracting a relatively narrow beam of light in, ahorizontal plane, and of refrae'ting an appreciably widerbeam of lightin a horizontal and downward direction.

3. A signal unit for street traflic control comprising a casing havingan opening, a lens or cover glass over said opening, said lens or coverglass having a band, including a plurality of prisms, extending acrossthe cover glass and parallel flutes on each side of said band, and anelectric lamp of appreciably low wattage in comparison with the highwattage standard of anproximately sixty watts customarily used in suchunits, said lamp disposed in said casing for illuminating the lens orcover glass, said lens or cover glass capable, in combination with saidlow wattage lamp, of retracting a relatively narrow beam of light in ahorizontal plane, and of refracting an appreciably wider beam of lightin a horizontal and downward direction.

CHARIES ADLER, JR.

